1. Field of the Invention
The present invention relates to cord fasteners for releasably engaging one or more cord segments to prevent movement of the cord segments relative to the fastener. More particularly, the invention relates to such cord fasteners that include spring mechanisms to urge the fastener toward a locking position.
2. Description of the Prior Art
Cord fasteners are used in many different applications to releasably retain one or more cord segments or drawstrings in a tightened condition and to release such cord segments when desired. For example, cord fasteners are used in connection with garments that include drawstrings, such as hooded jackets and sweatshirts. Such fasteners are also used on various types of bags such as laundry bags and other storage bags that utilize cords to temporarily close an open end thereof. These cord fasteners vary in size depending on the particular application, from less than one inch long to several inches or more.
A number of different cord fastener designs have been proposed by those skilled in the art. One such cord fastener device is disclosed in U.S. Pat. No. 4,156,574 and includes a cage that slidably receives a locking slide therein. The slide includes a pair of resilient, flexible feeler arms that extend laterally outwardly from the opposite sides of the slide body to engage the respective cord segments when those segments are extended through the cage. Thus, the feeler arms are continually in engagement with the cord segments as the cord segments are moved relative to the cage. Although this structure has proven to work extremely well in drawing the slide body toward its locking position, over time the continual passing of the cord segments over the feeler arms can cause the cord to fray, resulting in a shortened useful life of the cord.
Yet another prior art cord fastener, disclosed in U.S. Pat. No. 4,878,269, comprises a housing and a locking element, the locking element including a stationary segment fixedly connected to the housing and a movable segment displaceable relative to the housing. The stationary and movable segments are interconnected by means of a compression spring interposed therebetween. The compression spring continually urges the movable segment away from the stationary segment and into a cord locking position. The compression spring is continually in a state of compression, which can result in premature failure of the spring. Furthermore, it has been found that by utilizing a compression spring to continually urge the movable segment into the cord locking position, the device can be somewhat difficult to unlock, even under moderately heavy load conditions.
Still another prior art cord locking device is disclosed in U.S. Pat. No. 5,572,770, invented by an inventor of the subject matter of the present application. The device disclosed therein includes a cage and slide, with the slide having an integrally formed, outwardly protruding leaf spring to urge the slide into position. While this device is generally satisfactory, it does not provide a relatively low profiled cord lock apparatus, and is therefore undesirable for use in applications requiring such a device.
Accordingly, it will be apparent to those skilled in the art that there continues to be a need for a cord locking apparatus that is of a construction providing a relatively long useful life, that is relatively easy to manipulate between cord locking and cord releasing positions, and that incorporates an unexposed spring mechanism to provide a relatively low profile. Furthermore, there exists a need for a cord locking device that accommodates different sizes of cord segments. The present invention addresses these needs and others.